AGN feedback in isolated galaxies with a SMUGGLE multiphase ISM

Feedback from active galactic nuclei (AGNs) can strongly impact the host galaxies by driving high-velocity winds that impart substantial energy and momentum to the interstellar medium (ISM). In this work, we study the impact of these winds in isolated galaxies using high-resolution hydrodynamics simulations. Our simulations use the explicit ISM and stellar evolution model called Stars and MUltiphase Gas in GaLaxiEs. Additionally, using a super-Lagrangian refinement scheme, we resolve AGN feedback coupling to the ISM at ∼10–100 pc scales. We find that AGN feedback efficiently regulates the growth of supermassive black holes. However, its effect on star formation and outflows depends strongly on the relative strengths of AGN versus local stellar feedback and the geometrical structure of the gas disc. When the energy injected by AGN is subdominant to that of stellar feedback, there are no significant changes in the star formation rates or mass outflow rates of the host galaxy. Conversely, when the energy budget is dominated by the AGN, we see a significant decline in the star formation rates accompanied by an increase in outflows. Galaxies with thin gas discs like the Milky Way allow feedback to escape easily into the polar directions without doing much work on the ISM. In contrast, galaxies with thick and diffuse gas discs confine the initial expansion of the feedback bubble within the disc, resulting in more work done on the ISM. Phase space analysis indicates that outflows primarily comprise hot and diffuse gas, with a lack of cold and dense gas.